1. Field of the Invention
The present invention relates to a board design aiding apparatus which forms a simple laminate model by simplifying a designed board and calculates a thermal displacement of a board on the basis of the simple laminate model, a board design aiding method and a board design aiding program.
2. Description of Related Art
Heretofore, a wiring pattern design in a printed wiring board uses an automatic tool and the like on the basis of a design rule (a width, a thickness, an interval and the like of a wiring) and is manufactured without considering conditions of a material selection, a manufacturing process and the like. Therefore, a deflection (displacement quantity) and the like effected by influence of a temperature change in a temperature processing step might be sometimes increased after the printed wiring board has completed. In such a case, it is repeated to again manufacture the printed wiring board by altering the design.
As a conventional technique which can determine a position of a reinforcing section of a printed wiring board by a simple and more rational method, a technique is known comprising a step of embedding a dummy material lowered in rigidity in a groove section of a multi-surface printed board as compared with its peripheral portion, a step of obtaining a stress or deformation quality distribution of the groove section by performing a deforming simulation to the multi-surface printed board embedding a dummy material, and a step of specifying a high stress portion or a high deformation quantity portion in the groove section on the basis of the obtained stress or deformation quantity distribution (e.g., Patent Document 1: Japanese Patent Laid-Open Publication No. 10-93206).
However, since a problem becomes clear after a printed wiring board has been manufactured in the above-mentioned conventional technique, a repetition of a cycle of designing and manufacturing the printed wiring board has been increased to prolong a developing period and to increase its cost. If a problem considered in advance in the case that a displacement quantity is increased is intended to be predicted by using a three-dimensional analysis and the like, a huge number of factors have been brought about and, therefore, its prediction become very difficult.
Even in the above-mentioned patent reference I, the problem of predicting the displacement quantity according to a temperature of such a complicated printed wiring board cannot be solved.